Igniter for liquid fuel burners and the like



Oct. 25, 1960 J. w. YATES 2,957,517

IGNITER FOR LIQUID FUEL BURNERS AND THE LIKE Filed July 27. 1959 2 Sheets-Sheet 1 '5 4 H I 52 I 1 |6 6 ,4,,/-}//,c,,p,//,,,,/,NA

INVENTOR. JoHN W. YATES y m, & ymv

ATTORNEYS Oct. 25, 1960 J. w. YATES 2,957,517

IGNITER FOR LIQUID FUEL BURNERS AND THE LIKE Filed July 27. 1959 2 Sheets-Sheet 2 Fl E 4 INVENTOR.

JOHN W. YATES BY ATTOR N EYS United States Patent IGNITER FOR LIQUID FUEL BURNERS AND THE LIKE John w. Yates, 6005 6th St., Tampa 11, Fla.

Filed July 27, 1959, Ser. No. 829,785

6 Claims. (Cl. 158-91) This invention relates to an improved igniter for liquid fuel burners and more particularly for vaporizing oil burners.

While there are now available a number of types of igniters or pilots for various types of liquid fuel burners or heaters, the present invention relates to an improved liquid fuel igniter, specifically designed for vaporizing oil burners, which has many advantages over those known in the art. The new igniter lights fuel before it flows into a burner pot, thereby avoiding the possibility of an explosion which can occur if unignited fuel is supplied to a burner pot that is sufficiently hot from prior operation. The igniter, when operating, also supplies preheated fuel to the burner pot which enables the fuel to burn more completely with less smoke or soot than otherwise occurs if the burner pot is initially cold. In addition, the igniter has an automatic extinguishing feature which shuts it off after a short period of initial ignition, and after the burner pot has become sufficiently hot that continued burning will occur without smoking or possible quenching of the flame. Thus, the igniter will burn for, say, ten minutes, even though the burner operates continually thereafter. The automatic shut-off is accomplished without the use of any moving part whatsoever.

It is, therefore, a principal object of the invention to provide an improved igniter for liquid fuel burners.

Another object of the invention is to provide an igniter including automatic shutoif operable after a desired period of burner operation.

A further object of the invention is to provide an improved igniter including an automatic shutoff requiring no moving parts.

Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings, in which:

Fig. 1 is a somewhat schematic view, partially in cross section, showing a vaporizing oil burner and an associated igniter according to the invention;

Fig. 2 is a front view in elevation of the igniter shown in Fig. 1;

Fig. 3 is a view in cross section taken 3-3 of Fig. 2; and

Fig. 4 is a view of the igniter in perspective with parts broken away and parts in cross section.

Referring to the drawings, and more particularly to Fig. 1, a vaporizing oil burner, generally indicated at 10, includes a burner pot 12 located in a furnace or heater, the walls of which are outlined by dotted lines 14. Means for establishing a stream of air, such as an air blower 16'or a fan, supplies combustion air to the pot 12 in this instance, through a duct 18 and a line 20 supplies fuel from a source (not shown) to anigniter 22 located, at least in part, in the air stream. The fuel is ignited when delivered to the pot 12 through an outlet fuel line 24. When the temperature of the pot is above the ignition point of the fuel, which can occur if the burner is operated for a considerable period, introduction thereinto along the line 2,957,517 Patented Oct. 25, 1960 ice of unignited fuel, which is avoided in the instant apparatus, would make an explosion imminent. In addition, the igniter 22 preheats the fuel before supplying it to the pot, and thus enables clean burning and prevents the possibility of flame extinguishing, which possibility exists when fuel flows into a cold pot.

Referring to Figs. 2-4, the igniter 22 comprises a housing 26 which includes a main portion 28 and a side portion 30 separated therefrom by a deep recess 32 through which (combustion) air (in the duct 18) can flow to cool the main portion 28. A combustion chamber 34 (Figs. 3 and 4) in the main portion 28 contains a wick 36 supported on the bottom of the chamber 34 and extending upwardly adjacent an electrically-heated resistance coil 3-8 (Fig. 4). The coil 38 is connected through an insulating block 40, which is carried by a horizontal divider 42 to terminals 44 and 46 having wires 48 and 50 connected through a switch 52 (Fig. 1) to a suit-able source of current.

Air is supplied to the combustion chamber 34 through a scoop 54 (Figs. 1, 2, and 4) which gathers a portion of the air passing through the duct 18 (Fig. 1) or air from any other suitable source and supplies it to a plenum chamber 56 (Fig. 4) separated from the combustion chamber 34 by the divider 42. From the plenum chamber 56, the air passes through orifices 58 in the divider 42, through an outer passage 60, under a baffle 62, and through an inner air passage 64 which is separated from the outer one by the baffie 62. The air then passes downwardly through a third passage 66 formed between a U-shaped recess wall 68 and a dividing wall 70 which directs the air downwardly into the combustion chamber 34.

Fuel is supplied indirectly to the combustion chamber 34 from a first fuel chamber 72 (Figs. 3 and 4) defined by the U-shaped wall 68, the housing 26, a short dividing wall 74, and a short diagonal wall 76. The diagonal wall 76 has a notch 78 (Fig. 4) in the upper edge thereof over which fuel can spill to the bottom of the combustion chamber 34. A portion 'of the fuel is carried by the wick 36 from the bottom of the chamber 34 upwardly adjacent the coil 38 and is ignited thereby. The diagonal wall 76 also has a small hole 80 near the bottom thereof through which fuel also can flow to the combustion chamber' 34.

A portion of the fuel in the first fuel chamber 72 is delivered to a second fuel chamber 82 defined by the U-shaped recess wall 68, the short dividing wall 74, and the short diagonal wall 76. Two wicks 84 and 86, which can be of suitable tubing partially filled with fibers or wires to establish a wicking or capillary action, are provided for transferring fuel from the chamber 72 to the chamber 82. As the fuel in the second fuel chamber 82 rises, it flows through a liquid fuel passage 88 (Figs. 2-4), connecting the main portion 28 and the side portion 30 of the housing 26, and into the lower portions of the air passages 60 and 64. As the level of the fuel continues to rise in the second chamber 82, fuel continues to flow through the passage 88 and eventually contacts the lower edge of the baffle 62 thereby to close off the passage 60 and prevent flow of air to the combustion chamber 34 so that the flame therein is extinguished.

Part of the fuel from the second chamber 82 is delivered to the combustion chamber 34 by a single wick 90 which delivers fuel from the second chamber 82 more slowly than it is delivered to this fuel chamber, thus enabling the level of fuel therein to rise to a height equal to the fuel level in the first chamber 72, the latter level being controlled primarily by the height of the notch 78. It will be readily seen that the bafile 62 must extend below the maximum level of fuel in the second chamber 82 but above the minimum level of fuel therein to properly control flow of air through the passages 60 and 64.

In operation, with the coil 38 hot, fuel is delivered to the igniter through the line 20 into the first fuel chamber 72. The fuel level therein quickly rises in spite of the small flow of fuel through the hole 80 at the bottom of this chamber, and through the wicks 84 and 86 into the second chamber 82. Fuel soon overflows the first chamber 72 through the notch 78 to the bottom of the combustion chamber 34 and is carried by the wick 36 adjacent the coil 38, which causes ignition. The ignited fuel then flows down the outlet line 24 to the burner pot 12. In the meantime, the fuel level in the second chamber 82 rises and fuel flows through the passage 88 into the lower portions of the air passages 60 and 64. As the fuel continues to rise, it contacts the lower edge of the bafile 62 and closes off the passage 60. With combustion air cut off to the chamber 34, the flame therein is soon extinguished. However, fuel continues to flow to the pot 12, which by this time is well warmed up and fuel therein is burning fully. Such flow is over the notch 78 of the first chamber 72, across the bottom of the combustion chamber 34, and through the outlet line 24. At this time, the coil 38 can be deenergized by means of the switch 52, either manually or automatically through a timer or a flame detecting device in the combustion chamber 34. Fuel in the second chamber 82 continues to rise to its maximum level equal to that in the first fuel chamber 72 and continues to block the passage 60 so long as the burner continues to operate.

When the burner 10 is turned off, the air passage 60 should be cleared rapidly to enable ignition to again occur in the igniter 22 when the burner 10 is again turned on. The hole 80 enables the contents of the first chamber 72 to empty rapidly when the fuel is turned off. As the level of fuel in the first chamber 72 drops below the level in the second chamber 82, flow through the wicks 84 and 86 reverses so that fuel is now delivered from the second chamber 82 to the first chamber 72 and out the hole 80. The wick 90 continues to carry fuel from the second chamber 82 to the combustion chamber 34. Thus, the three wicks 84, 86, and 90 all now operate to empty the second chamber 82 so that combustion air can again flow freely through the passages 60 and 64 to the combustion chamber 34 when the burner is again turned on. It will be noted that the igniter 22 is so small relative to the burner pot 12 that the fuel drained from the former is negligible in the latter, and constitutes no hazard.

Various modifications of the above described preferred embodiment of the invention will be apparent to the reader. It is to be understood that such modifications can be made within the spirit of the invention as defined in depending claims.

I claim:

1. An igniter for a liquid fuel burner including a burner pot, a fuel line for supplying liquid fuel to the pot, and means for supplying air to the pot, said igniter comprising a housing, means forming a combustion chamber in said housing, a main wick in said chamber, an electrically heated coil adjacent said wick, wall means forming a first liquid fuel chamber in said housing, and defining a passage for the flow of fuel from the first fuel chamber to the combustion chamber when the level of fuel in said first chamber reaches a predetermined level, Wall means forming a second liquid fuel chamber in said housing, means for supplying liquid fuel to said first chamber, a wick connecting said first to said second fuel chamber, a wick connecting said second fuel chamber to said combustion chamber for delivering fuel from said second chamber to said combustion chamber, and effective to deliver fuel at a rate less than the delivery rate of fuel from said first chamber to said second chamber, wall means including a baffle forming an air passage from the air supply means to said combustion chamber, said baffle extending downwardly below the maximum level of fuel in the second chamber but above the minimum level of fuel in the second chamber, and a liquid fuel passage connecting the second chamber with said air passage adjacent said baffle whereby a portion of the fuel supplied to said first chamber is delivered to said second chamber and blocks the air passage as the fuel rises in the second chamber container.

2. An igniter for a liquid fuel burner including a burner pot, a fuel line for supplying liquid fuel to the pot, and means for supplying air to the pot, said igniter comprising a housing, means forming a combustion chamber in said housing, a main wick in said chamber, an igniting element adjacent said wick, wall means forming a first liquid fuel chamber in said housing, and defining a passage for the flow of fuel from the first fuel chamber to the combustion chamber when the level of fuel in said first chamber reaches a predetermined level, wall means forming a second liquid fuel chamber in said housing, means for supplying liquid fuel to said first fuel chamber, means for delivering fuel from said first chamber to said second chamber, means for delivering fuel from said second chamber to said combustion chamber and effective to deliver fuel at a rate less than the delivery rate of fuel from said first chamber to said second chamber, wall means including a baffie forming an air passage from the air supply means to said combustion chamber, said bafile extending downwardly below the maximum level of fuel in the second chamber but above the minimum level of fuel in the second chamber, and a liquid fuel passage connecting the second chamber with said air passage adjacent said bafile whereby a portion of the fuel supplied to said first chamber is delivered to said second chamber and blocks the air passage as the fuel rises in the second container.

3. An igniter for a liquid fuel burner including a burner pot, a fuel line for supplying liquid fuel to the pot, and means for supplying air to the pot, said igniter comprising a housing, means forming a combustion chamber in said housing, a main wick in said chamber, an igniting element adjacent said wick, wall means forming a first liquid fuel chamber in said housing, and defining a passage for the How of fuel from the first fuel chamber to the combustion chamber when the level of fuel in said first chamber reaches a predetermined level, wall means forming a second liquid fuel chamber in said housing, means for supplying liquid fuel to said first chamber, means for delivering fuel from said first chamber to said second chamber, wall means forming an air passage from a point outside said housing to said combustion chamber, a portion of said air passage being below the maximum level of fuel in the second chamber, a liquid fuel passage connecting the second chamber with the portion of said air passage whereby a part of the fuel supplied to sa d first chamber is delivered to said second chamber to block the air passage.

4. An igniter for a liquid fuel burner including a burner pot, a fuel line for supplying liquid fuel to the pot, and means for supplying air to the pot, said igniter comprf sing a housing, means forming a combustion chamber in said housing, means for igniting fuel in said combustion chamber, wall means forming a first liquid fuel chamber in said housing, and defining a passage for the flow of fuel from the first fuel chamber to the combustion chamber when the level of fuel in said first chamber reaches a predetermined level, wall means forming a second liquid fuel chamber in said housing, means for supplying liquid fuel to said first chamber, means for delivering fuel from said first chamber to said second chamber, Wall means forming an air passage from a point outside the housing to said combustion chamber, said passage having a portion extending downwardly below the maximum level of fuel in the second chamber, and means defining a liquid fuel passage connecting the second chamber with said air passage whereby a portion of the fuel supplied to said second container flows through said liquid air passage and blocks the air passage.

5. An igniter for liquid fuel burners and the like comprising a housing, means forming a combustion cham her in said housing, means for supplying liquid fuel to said combustion chamber, means for igniting fuel in said chamber, wall means forming a liquid fuel chamber in said housing, means for supplying liquid fuel to said fuel chamber, wall means forming an air passage from a point outside said housing to said combustion chamber, said passage having a portion extending downwardly below the maximum level of the fuel in the container, and means defining a liquid fuel passage connecting said fuel chamber with said air passage whereby fuel flowing through said liquid fuel passage from said fuel chamber will block said air passage.

6. An igniter for liquid fuel burners and the like comprising a housing, means forming a combustion chamber in said housing, means for supplying fuel to said chamber, means for igniting fuel in said chamber, wall means forming an air passage from a point outside said housing to said combustion chamber, said passage extending downwardly below the maximum level of fuel in said chamber, means forming a liquid fuel passage connecting said chamber with said air passage whereby a portion of the fuel supply to said chamber is delivered to said air passage and blocks the flow of air therethrough.

No references cited. 

